Skateboard



FIG. 1 is a rear elevational view of a skateboard, showing my new design;

FIG. 2 is a front elevational view thereof.

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a bottom plan thereof. 

The ornamental design for a skateboard, as shown. 